In a study of cell phone use and brain hemispheric dominance, an internet survey was e-mailed to 2457 subjects randomly selected from an online group involved with ears. 935 surveys were returned. construct a 95% confidence interval for the proportion of returned surveys.

find the best point estimate of the population proportion p.

identify the value of the margin of error e.

construct the confidence intreval.

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.

Which function has the domain x> -11?

Barney & noblet customers can choose to purchase a membership for $25 per year members receive 10% off all store purchases 1. how much would a member pay per year if he bought $50 worth of items each year? 2. write a slope-intercept equation that expresses how much a member pays per year using x to represent his purchases per year 3. how much would a member have to spend per year to pay off his membership fee?